Further fixes for REALLOC_ZERO_BYTES_FREES comment

* malloc/malloc.c (REALLOC_ZERO_BYTES_FREES): Improve comment further.
This commit is contained in:
Paul Eggert 2021-04-12 00:33:15 -07:00
parent 0385d5fff8
commit 9f1bed18f9

View File

@ -346,13 +346,14 @@ __malloc_assert (const char *assertion, const char *file, unsigned int line,
#define REVEAL_PTR(ptr) PROTECT_PTR (&ptr, ptr)
/*
REALLOC_ZERO_BYTES_FREES controls the behavior of realloc (p, 0)
when p is nonnull. If nonzero, realloc (p, 0) should free p and
return NULL. Otherwise, realloc (p, 0) should do the equivalent
of freeing p and returning what malloc (0) would return.
The REALLOC_ZERO_BYTES_FREES macro controls the behavior of realloc (p, 0)
when p is nonnull. If the macro is nonzero, the realloc call returns NULL;
otherwise, the call returns what malloc (0) would. In either case,
p is freed. Glibc uses a nonzero REALLOC_ZERO_BYTES_FREES, which
implements common historical practice.
ISO C17 says the behavior is implementation-defined here; glibc
follows historical practice and defines it to be nonzero.
ISO C17 says the realloc call has implementation-defined behavior,
and it might not even free p.
*/
#ifndef REALLOC_ZERO_BYTES_FREES